1. Field of the Invention
This invention relates to novel water-in-volatile silicone emulsifier concentrates and to personal-care emulsion compositions of the water-in-oil type, i.e., water-in-volatile silicone. More specifically, this invention also relates to dry feeling personal-care lotions, creams, hair dressings, and other compositions for application to the human skin or hair for the purposes of conditioning the skin, e.g., moisturizing the skin, providing anti-perspirant protection, providing protection from the sun, or for conditioning the hair to make it more manageable, to improve its wet and dry combability and reduce "fly away" tendency of the hair. In one aspect, the novel emulsifier concentrates contain water-in-volatile cyclic silicone and an emulsifier comprising trimethylsiloxy end-blocked polydiorganosiloxanes having one or more pendant polyoxyalkylene chain of a molecular weight of less than 1000 bonded to silicon through an alkylene group. The personal-care emulsions are made by mixing the emulsifier concentrate, which may or may not contain personal-care components soluble therein, with water up to 90 wt. % of the total composition wherein said water may or may not contain water soluble personal-care components.
2. Description of the Prior Art
Water-in-volatile silicone personal-care emulsion compositions are disclosed in British Pat. No. 1,158,139. These water-in-volatile silicone emulsions in which the only emulsifier is an organic emulsifier are lacking in stability, especially when the aqueous phase contains a dissolved solute. U.S. Pat. No. 3,489,690 describes certain water-in-oil emulsions using certain polyoxyalkylene alcohols as emulsifiers and a silicone oil in the oil phase. These emulsions can also be expected to be lacking in suitable stability, particularly if the aqueous phase contains a dissolved solute. British Pat. No. 1,221,156 discloses water-in-oil emulsions for use as ointment bases for skin protection and skin care agents and which contain organosiloxane-oxyalkylene block copolymers as the external phase containing from 50 to 85% water as the internal phase. However, this patent does not disclose or suggest the use of a volatile silicone liquid as the oil phase in which water is dispersed as the internal phase by means of a polyoxyalkylene substituted block copolymer as described and claimed herein.
U.S. Pat. No. 3,234,252 discloses aqueous lubricating compositions in the nature of emulsions containing siloxane-polyoxyalkylene copolymers as additives. It has been reported (U.S. Pat. No. 4,122,029) that when one attempts to prepare water in low viscosity polydimethylsiloxane emulsions using only a siloxane polyoxyalkylene copolymer as an emulsifier, suitable stable emulsions are not obtained.
U.S. Pat. No. 4,122,029 discloses that emulsion compositions comprising water-in-volatile polydimethylsiloxane fluid can be prepared by using mixtures of certain organic surfactants and certain polydiorganosiloxane-polyoxyalkylene copolymers as the mixture of emulsifying agents. According to the disclosure in '029, the presence of an organic surfactant is necessary and the molecular weight of the oxyalkylene chains in the polysiloxane-polyoxyalkylene copolymers must be at least 1000. However, molecular weights of the polyoxyalkylene chains utilized in '029 result in relatively high viscosity, relatively high molecular weight, materials and emulsions. In terms of performance in personal-care or cosmetic applications, the materials disclosed in this patent are very dull and waxy in appearance which is probably due to the high molecular weight of the polyalkylene chains which approach wax-like characteristics.
U.S. Pat. No. 4,311,695 discloses personal-care emulsions of the water-in-oil type in which a water-alcohol solution is described as being dispersed within a volatile silicone liquid (or paraffinic hydrocarbon liquid) utilizing a polydiorganosiloxane-polyoxyalkylene copolymer containing polyoxyalkylene chains having an average molecular weight of at least 1000. These compositions also tend to have a dull and wax-like appearance presumably because of the presence of relatively long polyoxyalkylene chains.
DiSapio and Starch in Cosmetics & Toiletries, Vol. 96, pp. 55-57, disclose personal-care products which appear to be substantially the same as the emulsions described in the above-mentioned U.S. Pat. Nos. 4,311,695 and 4,122,029.
U.S. Pat. No. 4,374,825 discloses oil-in-water emulsions containing a volatile liquid hydrocarbon or silicone, a non-ionic water soluble thickener of an organic nature and a cationic hair conditioner agent comprising quaternary ammonium salts also of an organic nature. U.S. Pat. No. 4,387,090 refers to a hair conditioner composition containing a volatile silicone agent and a hydrophobic polymeric thickening agent of an organic nature. There is no mention in these patents of the utilization of a polyoxyalkylene substituted polysiloxane as an emulsifier or dispersant.
British patent application No. 2102288A discloses a hair conditioning composition which contains volatile silicone and a quaternary nitrogen-containing agent of a polymeric or non-polymeric structure, a long chain fatty alcohol and a tertiary amidoamine. This disclosure however does not disclose water-in-oil emulsions and also fails to disclose the employment of a polyoxyalkylene substituted polysiloxane in which the polyoxyalkylene chains have a molecular weight of less than 1000.
None of the above-identified references discloses or teaches this invention, that is, they do not disclose, teach or suggest any water-in-silicone emulsifier concentrate containing a volatile silicone liquid, water and a polyoxyalkylene substituted polysiloxane in which each polyoxyalkylene chain has a molecular weight of less than 1000 or water-in-silicone emulsions containing personal-care components made from said concentrates.
The cosmetic industry has a high level of interest in emulsions containing volatile silicones, especially for hair care products. The rationale for this approach has been to reduce the amount of oily-type materials in hair conditioners which give rise to the "greasies", but at the same time provide good wet and dry combability and reduced fly away. Volatile silicones remain on the hair for 24 hours or less depending on a number of factors, so that as the hair is receiving increasing amounts of oil from the scalp the amount of volatile silicone on the hair is decreasing.